Yarn tensioning device for circular knitting machine



y 1959 c. P. BERG 2,896,435

YARN TENSIONING DEVICE FOR CIRCULAR KNITTING MACHINE Filed Aug 6. 1956136115 ATTORJVEY United States Patent Chester P. Berg, Birdsboro, Pa.,assignor to Manor Hosiery Mills, Inc., Birdsboro, Pa.

Application August 6, 1956, Serial No 602,378

1 Claim. 01. 66-146) This invention relates to circular knit hosieryand, more particularly, to a circular knitting machine, a yarntensioning attachment and to a method of knitting seamless hosiery,particularly the welt portion thereof.

The conventional method of knitting ladies seamless hosiery in circularknitting machines is to use preshrunk yarn, such as preshrunk nylonyarn, for knitting the welt portion, as well as other portions, so thathigh temperatures encountered in subsequent operations, such as thedyeing and preboarding operations, will not cause further shrinkage ofthe yarn. While the use of preshrunk nylon yarn avoids the disadvantagesof later shrinking of the yarn and of the welt, which would causediscomfort to the wearer, it has the outstanding disadvantage ofrequiring expensive yarn material since preshrunk nylon yarn is rathercostly. Furthermore, the use of preshrunk nylon yarn does not permitsufiicient stretchability in the welt portion, therefore isdisadvantageous since substantial flexibility is a desideratum in thewelt to give wearing comfort and eliminate formation of welt impressionson the wearers legs. Furthermore, preshrunk nylon yarns still causecertain defects in the welt such as distorted stitches sometimesreferred to as crows feet or hen tracks" resulting in unattractive andimperfect hosiery.

An object of this invention is to provide a novel method and apparatusfor circular knitting of hosiery of the seamless type, particularly thewelt or shadow-welt portions thereof, which will overcome the abovestated disadvantages.

A further object of this invention is to provide a novel method ofknitting and a novel tension controlling attachment for a circularknitting machine, which will enable the use of very inexpensive yarn inits raw state, that is without preshrinking, and thus consider-ablyreduce the cost of makingladies hosiery, and simultaneously improve thequality of the hosiery.

A more specific object of this invention is to provide a novel tensioncontrolling attachment for a circular knitting machine which will enableloose knitting with raw yarn for making the welt portion of ladiesseamless hosiery, thereby providing a considerable increase instretchability of the welt, as compared to knitting with preshrunk nylonyarn under tension, and giving an amazingly high degr of comfort to thewearer.

A more specific object of this invention is to provide in a tensioncontrol device for any seamless knitting machine a tension control meansresponsive to operations of the yarn feeding finger so as to effectloosening of the tension when raw yarn is being knitted to form the weltportion, or shadow-welt portion, and so as to elfect tighten ing of thetension when it is not being knitted.

Other objects and advantages of the invention will become more apparentfrom a study of the following specification taken with the accompanyingdrawing, wherein the single figure is a vertical elevational view of theyarn feeding and tensioning portion of a circular knitting machine andincluding a tension controlling attachment embodying the principles ofthe present invention.

Referring more particularly to the drawing, numeral 1 denotes a cone orbobbin supplying yarn 2 which is fed into a seamless knitting machine ofany type. In accordance with the present invention, yarn 2, instead ofbeing preshrunk, such as is the conventionally used preshrunk-S-turnnylons, is merely raw yarn, such as raw nylon yarn, as it comes from theproducer of nylon yarn, therefore, which yarn is very inexpensive incost and whose fibers are rather loosely held together. Yam 2 may be rawnylon from pern /2 turn only and is fed through an eye 3 looselysupported on a U-shaped bracket 4, which bracket is suspended from abranch 5 extending from a stand or post 6. A plurality of branches (notshown) similar to branch 5 extend from post 6, each of which supports asimilar U-shaped bracket and eye for guiding yarn coming from othercones (not shown). Also supported on the stand 6 is a yarn take-upbracket 7, partially shown, which is conventionally used in the Scottand Williams KN type circular knitting machine, and denoted as S.W.24,259 AX.

In accordance with the present invention, any suitable fastening meansis used for attaching the tension controlling device 10 to a stationarypart of the machine, such as the take-up bracket 7. For example, acylindrical or barrel shaped element 9 may serve as the fastening meansand has a screw threaded into its top portion for fastening the leafelement 8 of bracket 7 to its top portion and has a similar screw in itsbottom portion for fastening tension controlling device 10 to bracket 7by means of element 9.

The tension controlling device 10, itself, is well known in the art andforms a component part of the Scott and Williams machine. It comprises asolid bracket with downwardly extending end flanges 10a on which ispivotally mounted a rocker assembly including a plurality of arms 11, 12and 13 which are pivotally mounted in unison underneath the bracket. Thearms 11, 12 and 13 are slotted at one end. Mounted in the slots are eyes11a, 12a, and 13a, respectively, which are in registry and through whichthe yarn 2 passes. Rigidly secured to the side of the bracket of tensioncontrolling device 10 are a pair of spools 14 and 15 of ceramic or othersuitable material for guiding the yarn and for applying tension theretoin a manner to be described hereinafter. At one end of the bracket of 10is screw threaded a post 16 for adjustably supporting one end of a coilspring 17, the other end of which spring is connected to the otherextremity of arm 11, whereby spring 17 serves as a return spring forbiasing the arms 11, 12 and 13 clockwise to a position shown in dashoutline such that eyes 11a, 12a and 13a will align below the centralportions of spools 14 and 15, thus yarn will not contact the spools,thereby removing tension from the yarn.

In accordance with the present invention, a coil spring 18 is connected,at one end, to one extremity of arm 11, and at the other end, to the endof a yarn feed finger 19 and, more specifically, to the yarn feed fingerwhich controls the knitting of the welt or shadow-Welt portion of thehosiery. Spring 18 is connected to the appropriate yarn feed finger 19by means of wire 23.

Each of the yarn feed fingers 19 has a spring 20 connected to oneextremity of the finger, the other end of the spring 20 being connectedto the top flanged portion of plate 21. Springs 20 act as return springsfor biasing fingers 19 in a clockwise direction about pivot 22 as acenter. After yarn 2 has passed through the tension control device 10,it passes through an eye 26, thence through a groove formed in the endportion of finger 19 and finally is led to a conventional assembly ondial cap 24 which includes a yarn binder and a scissors-like cutter (notshown) for holding the thread and for cutting it in a manner well knownin the art. Such assembly, per se,

forms no part of the present invention since it is a well knowncomponent part of a circular knitting machine, such as a Scott andWilliams KN type.

In operation, yarn 2 is normally fed through the tension control devicewhen the arms 11, 12, and 13 are in theposition shown in full lines,that is, when the eyes 11a,-12a and 13a are in the paths of spools 14and 15, so thatthe thread will assume a sinuous path and engage thelower surfaces of spools 14 and 15 whereby the spools will effecttensioning of the yarn. However, let us assume that the welt-controllingfinger 19 is moved to the dash line position in order to effect knittingof the welt (or shadow-welt) portion of the hosiery. Immediately. beforethis takes place it will be noted that tension spring 18 is strongerthan return spring 17, therefore, will bias the rocker assembly, thatis, arms 11, 12 and 13, to the position shown in full lines, that is, inthe yarn tensioning position. But as soon as the appropriate finger 19which controls the knitting of the welt (such as the No. 2 finger) ismoved to the dash line position to effect such knitting it will lift thelower end extremity of wire 23 and thus relieve the tension on spring 18and enable return spring 17 to rotate the rocker arms 11, 12 and 13clockwise to the position shown in dash lines, that is, to thenon-tensioning position, whereby the yarn is passed solely through eyes11a, 12a, and 13a, without contacting the surfaces of spools 14 and 15,and thus knit the yarn is under no tension, that is, it is in loosecondition while it is being knitted to form the welt. As soon as theknitting of the welt has been completed, the finger 19 which was in theposition shown in dash outline, will now be moved in a well known mannerto the full line position, therefore again tensioning spring 18 so as toovercome the action of weaker spring 17 and restore the parts to theposition shown in full lines in the drawing, that is, to the yarntensioning position. Thus, the raw yarn for knitting any particularportion of the stocking, such as a welt or shadow-welt portion, or infact, any other portion, may be effectively controlled by the pivotalmovements of the particular figure 19 which controls the knitting of theparticular portion of the stocking. The yarn feed fingers needles, andassociated parts, which are well known in the circular knitting machineart, are shown in greater detail in Pons Patent 2,472,614, Lawson et al.Patent 1,757,434 and Pratt Patent 1,825,089.

In the practice of my invention, that is, in applying it to the Scottand Williams circular knitting machine type KN, the catalog springnumber 10,282 is removed and a new spring, denoted as 18 on the drawing,is substituted which spring is preferably about 3 inches long with acoil diameter of .187 x .015 inch wire diameter.

Flexible piano wire, denoted in the drawing by numeral 23, may be usedhaving a thickness of .023 inch and which is linked to spring finger 19on the welt controlling spring finger (catalog No. 205,523).

By knitting the welt portion, or shadow welt portion, with raw nylonyarn or other raw yarn, without tensioning, there will be produced avery stretchable welt portion having at least about 2 inches or moreadditional stretch than in preshrunk nylon welts. More specifically, thestretch is extended from perhaps 11 /2 inches to as much as 14 or 14 /2inches. cessity of preboarding and prevents crows feet, and similarknitting imperfections. considerably increased stretchability of thewelt of the finished hosiery results in an amazingly greater comfort inwear. And by using raw yarn of any linear polyarnide, such as nylon, orof other synthetic material, the cost of throwing is eliminated, as

It also eliminates the ne-,

well as the cost for preshrinking and twisting of the welt yarn. Inshort, the cost of making the stocking or other knit fabric isconsiderably reduced, whereas the quality is considerably increased,particularly as to stretchability of the welt as elimination ofimperfect knitting, such as crows feet and the like.

While the loose, raw yarn has been described above for the making of thewelt or shadow-welt portion, it should be noted that such yarn may alsobe knitted to form other portions of a stocking, and, in fact, ifdesired, the entire stocking, or perhaps other fabrics whereinstretchability is desired, as well as low cost in manufacture, forexample ladies undergarments, such as girdles, brassieres, and the like.

Thus it will be seen that I have provided a novel circularly knitstocking and a novel tension controlling device in the form of anattachment that can be incorporated in the tension control device of acircular knitting machine, or other seamless knitting machine, whereinthe tension of the yarn is controlled directly by the pivotal movementsof the yarn feed finger, whereby the yarn may be fed loosely or withouttension in the knitting of the welt or shadow welt-portion or otherdesired portion or portions of the stocking; also I have provided a veryinexpensive attachment to enable knitting of ladies hosiery and otherfabrics, wherein stretchability is desired, by the use of veryinexpensive raw yarn, such as raw nylon yarn, therefore considerablyreducing the cost of manufacture of such stockings and greatlyincreasing the stretchability, wearing comfort and perfection of theknit.

While I have illustrated and described a single specific embodiment ofmy invention, it will be understood that this is by way of illustrationonly, and that various changes and modifications may be made within thecontemplation of my invention and within the scope of the followingclaim.

I claim:

In a circular knitting machine including a cone of raw yarn, and a yarntensioning device comprising stationary aligned spools and a pluralityof rocker arms having registering eyes mounted adjacent the ends thereofwhich are adapted to selectively move into and out of alignment withsaid spools to effect tensioning or relieve it, respectively, a returnspring connected to said rocker arms and biasing them to the tensionrelieving position, a plurality of yarn feed fingers cooperable with theneedles of said machine, spring means connecting one of said feedfingers, which controls knitting of the welt of a stocking, with saidrocker arms against the action of said rocker arm return spring, wherebymovement of said feed finger to the welt knitting position will relievetension of said spring means and allow said return spring to move therocker arms to the non tensioning position so as to knit said welt withloose raw yarn to produce a welt having substantial stretchability.

References Cited in the file of this patent UNITED STATES PATENTS1,666,056 Epps Apr. 10, 1928 2,290,005 Toone July 14, 1942 2,332,738Meade Oct. 26, 1943 2,396,166 Faucette Mar. 5, 1946 2,500,337 Berg Mar.14, 1950 2,729,083 Rabinovitz Jan. 3, 1956 2,729,957 Pope Jan. 10, 19562,767,567 Jenard et al Oct. 23, 1956

